The deal was killed by Harden's medical history. According to an MLB source, the Red Sox pulled the plug after reviewing Harden's records and coming to the conclusion he would not be able to get through the season.

A review of medicals after an agreement on the parameters of the deal, according to a baseball source, led to uncertainty about what kind of contribution the Red Sox could expect from Harden down the stretch, and whether he would be able to make enough starts to justify the trade.

Harden has been on the disabled list 10 times in his nine-year career.

Harden said that after the game, general manager Billy Beane told him he'll be pitching on Tuesday for Oakland and he's not going anywhere.

Like everyone, Harden had most recently heard that he was Boston bound. Sources on the Boston end had told me that the deal was agreed upon and just waiting finalization, and judging by stories in much of the Boston and national media, everyone else was getting the same information ...

It's unclear what happened, but it's certainly no secret that Harden has been on the DL 10 times in his career. It's possible Boston was scared off by medical reports, certainly - and I know that they were expected to be looking at Harden's records tonight - but it's equally possible there was some other snafu. Or maybe the deal was never quite 100 percent nailed down to begin with, despite the large number of us all hearing the same thing. Or maybe Boston is veering a different direction.

No one from the A's side ever confirmed anything in the way of a trade, by the way. Not a one.

Only hours after the Red Sox were on the verge of acquiring the right-hander from the Oakland Athletics pending a physical exam, the trade has fallen through, a major-league source said early this morning. ...

The source didn't provide a reason for why the deal has unraveled. Asked if it still may be revived before the non-waiver trade deadline at 4 p.m., the source said, "Not counting on it."